Question

我在DB，国家和州有2个表。现在，当我根据选择选择国家时，它必须显示状态。

用于.rhtml文件中的国家/地区选择我正在使用如下：

<%= select_tag "User[country_id]", options_for_select(Country.all.collect{|x| [x.country,x.id]})%>

现在基于以上选择，我需要选择状态。

Answer 1

查看：

<%= select_tag
  :country_select, # name of selectbox
  options_from_collection_for_select(@myrecords, "id", "name"), # your options for this select box
  :'data-remote' => 'true', # important for UJS
  :'data-url' => url_for(:controller => 'MyController', :action => 'getdata'), # we get the data from here!
  :'data-type' => 'json' # tell jQuery to parse the response as JSON!
%>


<%= select_tag
  :state_select, # name of selectbox
  "<option>Please select something from country select!</option>"
%>

控制器：

class MyController < ApplicationController
  def getdata
    # this contains what has been selected in the first select box
    @data_from_country_select = params[:country_select]

    # we get the data for selectbox 2
    @data_for_state_select = MyModel.where(:some_id => @data_from_country_select).all

    # render an array in JSON containing arrays like:
    # [[:id1, :name1], [:id2, :name2]]
    render :json => @data_for_state_select.map{|c| [c.id, c.name]}
  end
end

使用Javascript：

$(document).ready(function() {

  // #country_select is the id of our first select box, if the ajax request has been successful,
  // an ajax:success event is triggered.

  $('#country_select').live('ajax:success', function(evt, data, status, xhr) {
    // get second selectbox by its id
    var selectbox2 = $('#state_select');

    // empty it
    selectbox2.empty();

    // we got a JSON array in data, iterate through it

    $.each(data, function(index, value) {
      // append an option
      var opt = $('<option/>');

      // value is an array: [:id, :name]
      opt.attr('value', value[0]);
      // set text
      opt.text(value[1]);
      // append to select
      opt.appendTo(selectbox2);
    });
  });

});

Answer 2

我个人从未尝试过这种方式，请在国家/地区下拉列表中尝试此代码。

"f.select_tag :state, State.where(country_id: c.id)"


<div class="field">
   <%= f.label :country %><br>
   <%= f.select :country_id, Country.all.map {|c| [c.name, c.id] }, {prompt:"Choose Country"} %>
</div>

Answer 3

您需要使用qtyElem来获取更新的productElem，如下所示：

ajax

您必须向states控制器添加#config/routes.rb resources :countries do get :state, on: :member #-> url.com/countries/:country_id/states/ end操作：

states

这将允许您在更改countries的值时向此控制器发送ajax请求：

#app/controllers/countries_controller.rb
class CountriesController < ApplicationController
   def states
      @country = Country.find params[:country_id]
      @states = @country.states
      respond_to do |format|
         format.json { render json: @states.to_json }
      end
   end
end

-

您还需要确保您的表单格式正确。

具体来说，您需要使用select代替#app/assets/javascripts/application.js $(document).on("change", "#countries", function(e){ url = "countries/" + $(this).val() + "/states"; $.get(url, function(data){ $.each(data,function(key, value){ $("#states").find('option').remove().end(); $("#states").append('<option value=' + key + '>' + value + '</option>'); }); }, "json") });：

form_for

如何根据铁路中的国家/地区选择选择状态？

3 个答案: